When ever I hold alt and look over an enemies gear to view what they have, my screen moves. This only seems to happen in windowed mode (I hate fullscreen because then I can't alt tab to look at hotkeys for help, etc.)

Even though I haven't played the later releases, I can encounter the bug back in 7609 randomly in fullscreen too.
Most of the times I can view the enemy's gear without problems, but every now and then hitting the ALT key while hovering over an opponent, the screen goes jumping up and down like crazy.

“Discipline is choosing between what you want now and what you want most.” - Abraham Lincoln

To clarify: does this happen only when you are viewing enemy equipment with [Alt], or always once you pressed the key?

Only when my mouse is directly over the enemy with alt held. My guess is for whatever reason the screen is trying to scroll (Maybe to make room for the box of info,) and when it scrolls, my cursor is obviously no longer over the enemy and the box goes away.